Browsing by Subject "2,1,3-benzoxadiazole"

Based on earlier studies, it was known that certain 2,1,3-benzoxadiazole molecules were active against Chlamydia pneumoniae -bacterium. The goal of this study was to gather more information about structure-activity relationships of the 2,1,3-benzoxadiazole molecules. The purpose of a research was to develop a synthesis route for 2,1,3-benzoxadiazole molecules and build a molecular library based on the results. Synthesized molecules were tested against Chlamydia pneumoniae -bacterium and Leishmania donovani -parasites. Chlamydia pneumoniae -bacterium causes acute upper and lower respiratory tract infections such as bronchitis. The symptoms of acute inflammation of the Chlamydia pneumoniae can vary considerably. Chlamydia pneumoniae can also cause chronic infections. Chronic infections are linked to economically important diseases such as atherosclerosis and asthma. Leishmaniosis is the second most common parasitic disease in humans after malaria. Leishmania donovani -parasite can cause fatal visceral leishmaniasis. Leishmaniasis kills more than 50 000 people each year. In recent years, medical treatment for leishmaniasis has encountered many problems. Some of the medicines have lost their efficiency and some of them cause serious side effects. Fully functional synthesis route was developed for a 2,1,3-benzoxadiazole derivatives. 4-Amino-2-nitro benzoic acid was used as a starting material. With a oxidative ring-closure reaction 2,1,3-benzoxadiazole-5-carboxyl acid was obtained. 2,1,3-benzoxadiazole-5-carbonitrile was synthesized from the corresponding carboxyl acid via amide intermediate. When 2,1,3-benzoxadiazole-5-carbonitrile was treated with hydroxylamine hydrochloride, carboximidamide was obtained, which was a common intermediate for all the final products. At the final stage N'-hydroxy-2,1,3-benzoxadiazole-5-carboximidamide was let to react with either phenyl isocyanate or phenyl isothiocyanate to give the final products. Development of a synthesis route proved to be challenging so at the end three final products were synthesized. One of the final products was tested against C. pneumoniae -bacterium in the Åbo Akademi, Turku. The test compound did not contain 2,1,3-benzoxadiazole ring structure and the result was in line with expectations. The compound was not active against C. pneumoniae at low concentrations and the results showed that 2,1,3-benzoxadiazole ring is an important part of the activity. Two of the final products were tested against Leishmania donovani parasite in Israel. Only one of the molecules contained 2,1,3-benzoxadiazole ring. The results of the bioactivity test were very encouraging. Compounds were active against the parasite at low concentrations. However, the 2,1,3-benzoxadiazole compound was more active. Also the result of Leishmania test shows that 2,1,3-benzoxadiazole ring structure was found to be an important part of the activity.